Thews



UNITED STAT PATENT OFFICE.

'JOHN BAYNES, OF BRONXDALE. ASSIGNOR TO THE FIRM OF JOHN 'MAT- THnws, on NEW YORK, N. Y.

PROCESS FOR PREPARING GLASS, METAL,"&.C., FOR EROSION.

SPECIFIGATION'fOrming part of Letters Patent No. 282,485, dated August 7, 1883.

. Application filed January 10, 1883. (No specimens.) i

To aZZ whom it may concern:

Be it known that I, JOHN BAYNES, of Bronx dale, in the county of Westchester and State of New York, have invented a new Process for Preparing Glass, Metal, or other Substances for Erosion, of which the following is a specification.

My invention relates to a new process for preparing glass, metals, or other substances for erosion. By the word erosion I mean the eating away of the glass or metal caused by the application of acid, the sand-blast, or other similar process for producing thedesired pat tern on the glass or metal. Various processes have been used to effect thisresult; but by my improvement hereinafter described a saving in expense is obtained, as well as a greater rapidity and facility in preparing the substance forerosion-in any desired pattern.

My improved process is as follows: The glass, metal, or other substance into which the pattern is to becut is coated' on its facewith a preparation or mixture composed of gumcopal, gum-kauri, or any gum which is soluble in oil of turpentine, or other well-known essential oils in which asphaltum is also soluble,

together with asphaltum and any such oil, in

the proportions of about ninety per cent. of asphaltum to ten per cent. of the gum. The

A translucent substance.

quantity of the oil used is according to the thickness or strength of which it is desired to make themixture or varnish. The proportions above given, however, maybe varied for diflerent circumstances and kinds of work. The varnish or mixture made as above described is applied to the surface of the glass, for example, by dipping or with a brush; or it ispowdered and spread over it if the mixture is used in a solid form. This mixture, compounded as above set forth, is sensitive to the action' of light, and forms a sensitized ground or resist. The design or pattern which it is desired to etch upon the glass is then placed over this resist, said design or pattern being fixed upon some transparent or Thus the design may be photographed, drawn, painted, or placed in any manner upon glass or paper or any other translucent material; or the design or pattern may be transferred directly to or.printed or placed on the sensitized mixture forming the coating of the glass to be etched, which coating I have called the resist, in any suitable manner. After thetransparentor translucent substance, with the design or pattern on it, is placed above the coated glass, the whole must be exposed to sunlight for a period of, i say, eight hours for ordinary work, though this period varies with the differences in the light and with the translucency of the material on which the design or pattern is set.

posure to the sunlight those portions of the coating or resist which do not lie below the pattern, and to which the light has free access through the translucent or transparent material above, are hardened, while the portions under the pattern and to whichthe sun has not free access remain soluble, and are readily ered and exposed in exactly the form of the pattern which was above it when exposed to the sun. This exposed portion is then readily etched by the use of acid or by sand-blast or any of the well-known processes.

, lVhen patterns are required to be arranged through the medium of spirit;varnis'hes, glue, or substances not soluble in the mediums in which the coating or resist is soluble, then the resist. maybe applied over a substratum of such spirit-varnish or similar substance, the latter being in direct contact with the substance to be etched, and after the exposure to the sun and the use of the solvent on the resist, as described, another suitable solvent can then be used upon the portions of the substratum left exposedby the action of the first solvent on the resist. A dye or pigment may be also applied, when desired, to materials capable of receiving it, while the insoluble parts of the resist remain, thus forming a dyed or colored design. i

The invention above described permits the use of printed paper as a pattern, through which paper the light acts on the resist.

I do not claim covering the glass or other substance with a mere mixture of oil and asphaltum, and then exposing'toflight. Sucha which light has upon it to be of any use in the position of asphaltum, of gum-copal, which is process of erosion. soluble in oil of turpentine, in which asphaL I claim tum is also soluble, and of such oil, in then su- I 5 1. The composition of asphaltum with gumperimposing the pattern directly upon said 5 copal, which is soluble in oil of turpentine, in composition, in then exposing to the sunlight, which asphaltum is also soluble, and of such and finally using a solvent and taking off that oil, in about the proportions mentioned, foruse portion of the composition remaining unsoas a resist in erosive processes, substantially lidified, all substantially as described.

as described. JOHN BAYNESL 1o 2. The process herein described of prepar- Witnesses:

ing substances for erosion, which process con- GEO. LUcE,

sists in first applying to the substance a com- MAX LEBE. 

